From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39436) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bKgt1-0001M3-Ez for qemu-devel@nongnu.org; Wed, 06 Jul 2016 03:04:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bKgsy-0003mf-3q for qemu-devel@nongnu.org; Wed, 06 Jul 2016 03:04:43 -0400 Received: from 3.mo4.mail-out.ovh.net ([46.105.57.129]:48613) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bKgsx-0003mX-TO for qemu-devel@nongnu.org; Wed, 06 Jul 2016 03:04:40 -0400 Received: from player687.ha.ovh.net (b9.ovh.net [213.186.33.59]) by mo4.mail-out.ovh.net (Postfix) with ESMTP id 4F0F11024DDC for ; Wed, 6 Jul 2016 09:04:39 +0200 (CEST) Date: Wed, 6 Jul 2016 09:04:30 +0200 From: Greg Kurz Message-ID: <20160706090430.2c8d5ef3@bahia.lan> In-Reply-To: References: <1467729757-12441-1-git-send-email-lvivier@redhat.com> <20160706013529.GT2251@voom.fritz.box> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/AXsM_6uCE0=mZVWJS2q7I_2"; protocol="application/pgp-signature" Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH RFC] spapr: by-pass SLOF when -kernel is provided List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: David Gibson , Laurent Vivier , Andrew Jones , qemu-ppc@nongnu.org, Thomas Huth "Richard W.M. Jones" , qemu-devel@nongnu.org --Sig_/AXsM_6uCE0=mZVWJS2q7I_2 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Wed, 6 Jul 2016 13:33:49 +1000 Alexey Kardashevskiy wrote: > On 06/07/16 11:35, David Gibson wrote: > > On Tue, Jul 05, 2016 at 04:42:37PM +0200, Laurent Vivier wrote: =20 > >> As device-tree is now fully built by QEMU, we don't need SLOF > >> anymore if the kernel is provided on the command line. > >> > >> In this case, don't load SLOF and boot directly into the > >> kernel. > >> > >> This saves at least 5 seconds on the boot sequence. > >> > >> Signed-off-by: Laurent Vivier =20 > >=20 > > I'm not comfortable applying this. We actually used to do this ages > > ago, but changed to always running through SLOF, and there were > > reasons for doing so. > >=20 > > I don't remember exactly what they were, but I think it boiled down to > > slight differences in state between booting from SLOF and booting > > without SLOF leading to confusing errors from the guest kernel. > > =20 >=20 > PCI resource allocation is still done by SLOF (however having them not set > will trigger allocation in the guest but this is rather unexpected > workaround than a feature); "client-architecture-support" won't work > without SLOF either (i.e. compatibile PowerISA 2.0x CPUs). >=20 Not even sure the workaround actually works: I retried with a ppc64le guest and this time I get: [ 1.055922] virtio-pci 0000:00:01.0: virtio_pci: leaving for legacy driv= er [ 1.056048] virtio-pci: probe of 0000:00:01.0 failed with error -12 [ 1.056263] virtio-pci 0000:00:00.0: virtio_pci: leaving for legacy driv= er [ 1.056373] virtio-pci: probe of 0000:00:00.0 failed with error -12 i.e. virtio_reset() isn't called during probing :-\ -- Greg --Sig_/AXsM_6uCE0=mZVWJS2q7I_2 Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAld8rX4ACgkQAvw66wEB28JeJwCfewWa8iYI3Et761sTlA9JCDst DiIAnRtcVpgfkHl0zDoDsTGgO6nKvsb5 =BcAf -----END PGP SIGNATURE----- --Sig_/AXsM_6uCE0=mZVWJS2q7I_2--